1. Field of the Invention
The present invention relates to an image reading apparatus and more specifically to an image reading apparatus which includes a plurality of reading sections and reads a photographic photosensitive material by predetermined plural reading sections among the plurality of reading sections.
2. Description of the Related Art
There has been conventionally proposed an image reading apparatus in which a photographic film is conveyed by a film carrier, and the conveyed photographic film is read via an imaging lens by a CCD line sensor comprised of a plurality of CCD elements arrayed in a direction perpendicular to a conveying direction of the photographic film. In this type of image reading apparatus, a range of the photographic film to be read is read by predetermined plural CCD elements of the plurality of CCD elements such that images of unnecessary portions are not read.
In this image reading apparatus, when the photographic film is read with the magnification thereof changed (i.e., enlargement or reduction thereof is carried out), the CCD line sensor is moved so as to approach and away from the photographic film.
However, since the CCD line sensor is movable with respect to the photographic film as described above, due to vibration or the like, the positions of the CCD line sensor, the imaging lens (the optical axis), the film carrier, and the like may deviate from their proper positions. When the CCD line sensor and the like deviate from their proper positions, the reading range, which is read by the predetermined plural CCD elements of the plurality of CCD elements, deviates from the range of the photographic film to be read. As a result, the range of the photographic film to be read cannot be read.
In order to solve this problem, there has been considered a structure in which the CCD line sensor and the photographic film are mechanically moved, but the mechanical structure thereof is complex.
The present invention was devised in order to solve the above-described drawbacks, and an object of the present invention is to provide an image reading apparatus which is able to read a photographic photosensitive material properly.
To accomplish the above-described object, an image reading apparatus of the first aspect of the present invention comprises: reading means including a plurality of reading sections, the reading sections reading an image of a reference position which is used as reference with respect to a photographic photosensitive material imaged thereon; and determination means for determining a range of the plurality of the reading sections for reading the photosensitive material. The determination means includes: calculation means which calculates a value which indicates an amount of deviation between an actual reading position, at which the reference position is actually imaged and read by said reading means, and a proper reading position, at which the reference position should be imaged and read; and changing means which changes the range of the plural reading sections for reading the photographic photosensitive material from an initially determined range of the plurality of the reading sections to another range, on the basis of the value indicating the amount of deviation calculated by said calculation means.
Further, in a second aspect of the present invention, the changing means changes the range of the plural reading sections selected for reading the photosensitive material in a direction in which the amount of deviation is eliminated, so that at least the predetermined range to be read of the photosensitive material is read by the range of the plural reading sections.
According to the first and second aspects of the present invention, on the basis of a value indicating the amount of deviation between an actual reading position and a predetermined proper reading position, a plurality of reading sections which read a photosensitive material are shifted from predetermined plural reading sections in a direction in which the deviation is eliminated and within a range in which the deviation is eliminated. Accordingly, even if the reading means deviates from its proper position, the entire range to be read of the photosensitive material can be reliably read.
In a third aspect of the present invention, the image reading apparatus further comprises conveying means which conveys the photosensitive material, wherein the plural reading sections are disposed in a direction intersecting a conveying direction of the photosensitive material, and the reading means reads the photosensitive material at the time of conveying of the photosensitive material by the conveying means.
The reading time can be reduced because a plurality of reading sections, which are aligned in a direction intersecting the direction in which the photosensitive material is conveyed, read the photosensitive material during the conveying thereof.
In a fourth aspect of the present invention, the reading means carries out preliminary reading (pre-scan) and main reading (fine-scan) of the photosensitive material conveyed by the conveying means, and the determination means carries out the determination after the reading means completes the preliminary reading and before the reading means begins the main reading.
In a fifth aspect of the present invention, the determination means carries out the determination for each of the images recorded on the photographic photosensitive material at at least one of the following points in time: before each image frame is read; each time an image frame is read in the main scan direction; each time the conveying means is mounted; each time the conveying means is removed; and each time an image is read at a changed magnification.
In accordance with a sixth aspect of the present invention, the present invention further comprises imaging means which is able to image an image recorded on the photographic photosensitive material on the reading means at an enlarging/reducing magnification; and adjusting means which adjusts the imaging means such that the image recorded on the photographic photosensitive material is imaged on the reading means at an enlarging/reducing magnification; wherein the determination means carries out the determination each time the imaging means is adjusted by the adjusting means. Namely, the imaging means is adjusted by the adjusting means. For example, the imaging means is made to approach and move away from the photographic photosensitive material by the adjusting means. When the imaging means is formed by a combination of lenses, the distance between the lenses is changed by the adjusting means. In this way, the photographic photosensitive material is imaged to the reading means at an enlarging/reducing magnification. At this time, the changing means may carry out change each time the imaging means is adjusted by the adjusting means.
In accordance with a seventh aspect of the present invention, the reading means may be photo-receiving-elements-for-reading. An appropriate number of photo-receiving-elements-for-reading necessary for the reading means to read the photographic photosensitive material after the magnification has been changed, is calculated on the basis of a number of photo-receiving-elements-for-reading necessary for the reading means to read at a predetermined magnification a reference region including the reference position, a number of photo-receiving-elements-for-reading necessary for the reading means to read the photographic photosensitive material at a predetermined magnification, and an actual number of photo-receiving-elements-for-reading necessary for the reading means to read the reference region after the magnification is changed (i.e., after the imaging means is adjusted by the adjusting means).
Then, a range of a plurality of photo-receiving elements to read the photographic photosensitive material is determined by said determination means on the basis of the calculated number of photo-receiving-elements-for-reading necessary for the reading means to read the photographic photosensitive material, an actual number of photo-receiving-elements-for-reading necessary for the reading means to read the reference region after the magnification has been changed, and the position of photo-receiving elements which read the reference region.
In accordance with the seventh aspect, the appropriate number of photo-receiving-elements-for-reading, for reading the photographic photosensitive material, which number overcomes the magnification error caused by the deviation of the imaging means, can be obtained. Therefore, all regions of the photographic photosensitive material to be read can be reliably read regardless of the magnification error due to the deviation of the imaging means.
In an eighth aspect of the present invention, the present invention further comprises imaging means which is able to image an image recorded on the photographic photosensitive material on the reading means at an enlarging/reducing magnification; adjusting means which adjusts the imaging means such that the image recorded on the photographic photosensitive material is imaged on the reading means at an enlarging/reducing magnification; and control means which controls the position of the adjusting means so that the imaging means is adjusted, on the basis of the number of photo-receiving-elements-for-reading necessary for said reading means to read at a predetermined magnification the reference region including the reference position, a number of photo-receiving-elements-for-reading necessary for the reading means to read the photographic photosensitive material at a predetermined magnification, and the actual number of photo-receiving-elements-for-reading necessary for the reading means to read the reference region after the magnification has been changed.
In accordance with the eighth aspect, the magnification error between the desired set magnification and the actual magnification is calculated on the basis of the number of photo-receiving-elements-for-reading necessary for the reading means to read at predetermined magnification the reference region including the reference position, the number of photo-receiving-elements-for-reading necessary for the reading means to read the photographic photosensitive material at a predetermined magnification, and the actual number of photo-receiving-elements-for-reading necessary for the reading means to read the reference region after the magnification is changed. By using the determined magnification error, the amount of adjustment by which the imaging means is to be adjusted in order to image the photographic photosensitive material to the reading means at the desired set magnification is determined. Accordingly, the imaging means is adjusted by the adjusting means on the basis of this amount of adjustment. Because the imaging means is readjusted in accordance with the magnification error, the photographic photosensitive material can be read at the proper magnification.